1. Field of the Invention
The present invention relates to a method and an arrangement for controlling a motor vehicle power unit consisting of an internal-combustion engine and variable-ratio, particularly hydrostatic-mechanical power take-off transmission, wherein the fuel supply to the internal-combustion engine and the transmission ratio are influenced through the intermediary of actuating elements.
2. Discussion of the Prior Art
Control arrangements for motor vehicle power units are presently known. German DE-OS No. 28 11 574 discloses a control requiring switches for selecting among various performance characteristics, depending on the vehicle operating condition, to affect the operation of the throttle or of the injection pump control lever. For example, in order to have a rapidly rising power output available, the angular velocity of the accelerator pedal is additionally measured to enable a changeover to optimum power output control. However, changeover cannot satisfy more than a single optimization criterion at any time.
In a known control arrangement of this type, as shown in German DE-OS No. 28 43 256, the switches are replaced by a so-called cross-controller enabling effectuation of a continual transition between performance-oriented and consumption-oriented optimizations of the operating mode.
However, in this arrangement it is disadvantageous in that flexible and very accurate correlation with different engine and transmission properties is not possible because of the predominantly mechanical-hydraulic operation of the control arrangement.